Variation in SNPs of theIL7RaGene is Associated with Multiple Sclerosis in the Iranian Population

Interleukin-7 receptor-alpha gene (IL7Ra) is a member of the type I cytokine receptor family located on 5p13 human chromosome. Some evidence associates multiple sclerosis and single nucleotide polymorphisms in the promoter and exonic region of IL7Ra gene. In an attempt to clarify this association, the frequency of 3 SNPs located in the promoter and 1 SNP located in the 6th exon of IL7Ra gene were analyzed in a population of 100 Iranian MS patients as well as 100 controls. Restriction enzyme digestion and a designed mismatch PCR-RFLP strategy were used for the SNP genotyping of our study groups. Considering allele, genotype and haplotype frequencies, no significant association was observed between MS and IL7Ra polymorphisms. Meanwhile, a significant difference was detected between control and primary progressive MS patients considering promoter SNPrs11567685 marker frequency. Also, a significant difference was detected considering exonic SNPrs6897932 for secondary progressive MS patients. Our analysis indicates that GCAC and GTAT haplotypes are less common in SP and PP MS groups, respectively. These differences support the concept that clinical phenotypes may have different etiologies and, therefore, require different therapy strategies.